Warm up

If you're starting a new exercise regime, don't overdo it. Slowly build the amount of exercise you do. If you can't manage 30 minutes in one go, break it up into 10-minute chunks.

Always warm-up for up to 10 minutes before you start. Walk at a brisk pace, or jog to warm your muscles.

Make sure you're warm if you're going outside. Wear several layers to keep the heat in. A lot of heat escapes through your head, so consider wearing a hat as well.

Stay safe

If you're exercising after dark, keep to well-lit areas and wear bright and reflective clothing. Ideally, exercise with a friend, but always tell someone where you're going.

Avoid listening to music while running outdoors. Not hearing what's going on around you can make you vulnerable.

If rain or ice is making exercise dangerous, do it another day. The weather might be better tomorrow, but an injury could take weeks to heal.

If you have a cold

Colds are more common in winter, but you don't necessarily have to stop exercising if you're feeling under the weather. According to Dr Keith Hopcroft, a GP from Basildon in Essex, use common sense and listen to your body.

"If your symptoms are not severe and you generally feel OK, then you can exercise. If you feel absolutely rotten, then it's best not to go."

However, it is important not to exercise if you have a fever. A fever is when your body's temperature is 38C (100.4F) or above and is rarely a symptom of a cold.

"If you exercise with a fever," says Dr Hopcroft, "it'll make you feel worse. In very rare cases, exercising with a fever can lead to the virus affecting your heart, which can be dangerous."

If you have asthma, take extra care when exercising in winter as cold air can trigger symptoms. Use your inhaler before you exercise and have it with you during your activity.